Using code given by Siemens is preferred. The secret of a totalizer is to keep values in integers as far as possible.

The code segment quoted below has a problem that occurs when using REAL numbers. Consider the equation Y = A + B, where all are REAL numbers. Assume A is much bigger than B. Then Y = A where B has no influence to the answer of the equation.

Many forum topics have been posted about the above problem.

SMIT SHAH

 This could be the code in your standard block

//////in_var

1. Scan_time : dint : // read the scan time of the OB in which you would like to call this block;

2. Flow_Real : real : // real value of the flow

3. en_totalize : bool :// start command for totalizer

4. reset :bool: // reset the accumulated value of totalizer

///////////////////////////////////////////

/////inout_var

Sample: real : //this is sample per scan of the block

Totalizzer :real : //this is your total accumulated value

/////////////////////////////////////////////////////////////////

Sample := Flow_Real / Dint_to_real (Scan_Time);

//////// Reset the totalizer ///////////

if reset then

Totalizer := 0.0;

end_if;

if en_totalize then

Totalizer :=  Totalizer + Sample;

end_if;

You can add 3 to 4 other totalizing real variables in inout section to have it totalize on different enable bits on the inputs side.

If i were to use it i would go for a standard UDT inclusive of all the variables in UDT except the Scan of the block and the Flow_Sensor value and call it in FC .

If now too any doubts don't hesitate to write me back.

Cheers guys!!